org.apache.commons.collections4.map
Class PredicatedMap<K,V>

java.lang.Object
  extended by org.apache.commons.collections4.map.AbstractIterableMap<K,V>
      extended by org.apache.commons.collections4.map.AbstractMapDecorator<K,V>
          extended by org.apache.commons.collections4.map.PredicatedMap<K,V>
All Implemented Interfaces:
Serializable, Map<K,V>, Get<K,V>, IterableGet<K,V>, IterableMap<K,V>, Put<K,V>
Direct Known Subclasses:
PredicatedSortedMap

public class PredicatedMap<K,V>
extends AbstractMapDecorator<K,V>
implements Serializable

Decorates another Map to validate that additions match a specified predicate.

This map exists to provide validation for the decorated map. It is normally created to decorate an empty map. If an object cannot be added to the map, an IllegalArgumentException is thrown.

One usage would be to ensure that no null keys are added to the map.

Map map = PredicatedSet.decorate(new HashMap(), NotNullPredicate.INSTANCE, null);

Note that PredicatedMap is not synchronized and is not thread-safe. If you wish to use this map from multiple threads concurrently, you must use appropriate synchronization. The simplest approach is to wrap this map using Collections.synchronizedMap(Map). This class may throw exceptions when accessed by concurrent threads without synchronization.

This class is Serializable from Commons Collections 3.1.

Since:
3.0
Version:
$Id: PredicatedMap.java 1479407 2013-05-05 22:07:53Z tn $
See Also:
Serialized Form

Nested Class Summary
 
Nested classes/interfaces inherited from interface java.util.Map
Map.Entry<K,V>
 
Field Summary
protected  Predicate<? super K> keyPredicate
          The key predicate to use
protected  Predicate<? super V> valuePredicate
          The value predicate to use
 
Constructor Summary
protected PredicatedMap(Map<K,V> map, Predicate<? super K> keyPredicate, Predicate<? super V> valuePredicate)
          Constructor that wraps (not copies).
 
Method Summary
protected  V checkSetValue(V value)
          Override to validate an object set into the map via setValue.
 Set<Map.Entry<K,V>> entrySet()
           
protected  boolean isSetValueChecking()
          Override to only return true when there is a value transformer.
static
<K,V> PredicatedMap<K,V>
predicatedMap(Map<K,V> map, Predicate<? super K> keyPredicate, Predicate<? super V> valuePredicate)
          Factory method to create a predicated (validating) map.
 V put(K key, V value)
          Note that the return type is Object, rather than V as in the Map interface.
 void putAll(Map<? extends K,? extends V> mapToCopy)
           
protected  void validate(K key, V value)
          Validates a key value pair.
 
Methods inherited from class org.apache.commons.collections4.map.AbstractMapDecorator
clear, containsKey, containsValue, decorated, equals, get, hashCode, isEmpty, keySet, remove, size, toString, values
 
Methods inherited from class org.apache.commons.collections4.map.AbstractIterableMap
mapIterator
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
 

Field Detail

keyPredicate

protected final Predicate<? super K> keyPredicate
The key predicate to use


valuePredicate

protected final Predicate<? super V> valuePredicate
The value predicate to use

Constructor Detail

PredicatedMap

protected PredicatedMap(Map<K,V> map,
                        Predicate<? super K> keyPredicate,
                        Predicate<? super V> valuePredicate)
Constructor that wraps (not copies).

Parameters:
map - the map to decorate, must not be null
keyPredicate - the predicate to validate the keys, null means no check
valuePredicate - the predicate to validate to values, null means no check
Throws:
IllegalArgumentException - if the map is null
Method Detail

predicatedMap

public static <K,V> PredicatedMap<K,V> predicatedMap(Map<K,V> map,
                                                     Predicate<? super K> keyPredicate,
                                                     Predicate<? super V> valuePredicate)
Factory method to create a predicated (validating) map.

If there are any elements already in the list being decorated, they are validated.

Type Parameters:
K - the key type
V - the value type
Parameters:
map - the map to decorate, must not be null
keyPredicate - the predicate to validate the keys, null means no check
valuePredicate - the predicate to validate to values, null means no check
Returns:
a new predicated map
Throws:
IllegalArgumentException - if the map is null
Since:
4.0

validate

protected void validate(K key,
                        V value)
Validates a key value pair.

Parameters:
key - the key to validate
value - the value to validate
Throws:
IllegalArgumentException - if invalid

checkSetValue

protected V checkSetValue(V value)
Override to validate an object set into the map via setValue.

Parameters:
value - the value to validate
Returns:
the value itself
Throws:
IllegalArgumentException - if invalid
Since:
3.1

isSetValueChecking

protected boolean isSetValueChecking()
Override to only return true when there is a value transformer.

Returns:
true if a value predicate is in use
Since:
3.1

put

public V put(K key,
             V value)
Description copied from interface: Put
Note that the return type is Object, rather than V as in the Map interface. See the class Javadoc for further info.

Specified by:
put in interface Map<K,V>
Specified by:
put in interface Put<K,V>
Overrides:
put in class AbstractMapDecorator<K,V>
See Also:
Map.put(Object, Object)

putAll

public void putAll(Map<? extends K,? extends V> mapToCopy)
Specified by:
putAll in interface Map<K,V>
Specified by:
putAll in interface Put<K,V>
Overrides:
putAll in class AbstractMapDecorator<K,V>
See Also:
Map.putAll(Map)

entrySet

public Set<Map.Entry<K,V>> entrySet()
Specified by:
entrySet in interface Map<K,V>
Specified by:
entrySet in interface Get<K,V>
Overrides:
entrySet in class AbstractMapDecorator<K,V>
See Also:
Map.entrySet()


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